A pressure sensor provided with a diaphragm structure which detects a change in measurement target pressure as a change in electric capacitance has been conventionally widely known. As an example of this pressure sensor, there is a pressure sensor in which a movable plate is joined near a strain generating region on a vacuum chamber side of a diaphragm and a movable electrode and a fixed electrode are respectively formed on opposed surfaces of an outer peripheral portion of the movable plate and a fixed portion of the diaphragm to detect a change in electric capacitance between these electrodes as a change in pressure (see, e.g., Japanese Patent Application Laid-open No. 2002-267559 as Patent Document 1).
Further, there is also considered a pressure sensor having a structure in which a sensor chip is supported in a metal frame body of a package through a metal plate, a cover plate and a buffer member to securely support the sensor chip in the package and the cover plate is held and constrained between the metal plate and a base.
Patent Document 1: Japanese Patent Application Laid-open No. 2002-267559